Conciseness

Three lean paragraphs (~70 words) with zero padding and no explanation of concepts Claude already knows — 'Storybook must end up at 11.0 or later. An 11.0 prerelease (11.0.0-alpha.x) or a canary build (0.0.0-pr-*) also counts.' Every token earns its place, matching 'Lean and efficient; assumes Claude's competence'. The version numbers are the task's target, not incidental time-sensitive content, so no penalty applies.

Actionability

The fallback path is fully executable ('upgrade to the 11.0 alpha with npx storybook@next upgrade') and the success criterion is concrete ('must end up at 11.0 or later'), matching 'Mostly executable guidance; concrete code or commands with minor gaps'. It is not a 5 because the primary upgrade path delegates entirely to an external URL ('Read ... in its entirety') with no inline copy-paste command for the standard case.

Workflow Clarity

The logic is clear: a defined end state ('Storybook must end up at 11.0 or later'), an instruction to read the upgrade guide, and an explicit conditional branch ('If the latest stable release is below 11.0, upgrade to the 11.0 alpha ... instead'), matching 'Clear sequence with most checkpoints present; minor validation gaps'. It is not a 5 because there is no explicit post-upgrade verification step (e.g., how to check the installed Storybook version) to confirm the end state was reached.

Progressive Disclosure

The skill is well under 50 lines with no bundle files, and all content belongs inline; the only pointer is a one-level-deep external URL that is clearly signaled ('Read https://storybook.js.org/docs/releases/upgrading.md in its entirety'). Per the rubric's simple-skill note, this matches the top anchor — no trimming or splitting is warranted at this size.

Specificity

The description names the domain ('Storybook') and one concrete action ('upgrade'), matching 'Names domain and 1-2 concrete actions, but not comprehensive'. It is above a score of 2 because 'upgrade' is a specific action rather than generic handling like 'Processes PDF files', but below 4 because only one action is named and details like the target version are absent.

Completeness

The 'when' is explicit ('when Storybook exists but needs an upgrade'), but the 'what' is only weakly implied through the word 'upgrade' inside the when-clause rather than stated as a capability (e.g., 'Upgrades Storybook projects to 11.0 or later'). This sits between anchor 2 ('only when present without what') and anchor 4 (both present with when improvable): the what is discernible but not explicit.

Trigger Term Quality

'Storybook' and 'upgrade' are relevant natural keywords, but common variations users would say — 'update Storybook', 'migrate Storybook', 'Storybook is out of date', or version references like 'Storybook 11' — are missing, matching 'Some relevant keywords but missing common variations or synonyms'. It is not a 4 because coverage is thin beyond those two terms.

Distinctiveness Conflict Risk

'Storybook' is a specific named tool with a distinct action ('upgrade'), giving a clear niche with minimal conflict risk against other skills. It fully matches the anchor 'Clear niche with distinct triggers; minimal conflict risk' and is not below 5 since no broader overlap terms appear.